The middenstand is the middle class.
Middenstanders are typically self-employed. Historically, most Dutch people who were considered middle class were either business owners or had a trade. 
Aunt Piet Trouw (in white apron) before her shop in Princenhage (public domain)
About Yvette HoitinkYvette Hoitink, MLitt, CG®, QG™ is a professional genealogist, writer, and lecturer in the Netherlands. She has a Master of Letters in Family and Local History from the University of Dundee, and holds the Certification of Genealogist and Qualified Genealogist credentials. Yvette served on the Board of Directors of the Association of Professional Genealogists and won excellence awards for her articles in the National Genealogical Society Quarterly and the Association of Professional Genealogists Quarterly. Yvette has been doing genealogy for over 30 years. She helps people from across the world find their ancestors from the Netherlands and its former colonies, including New Netherland. Read about Yvette's professional genealogy services.
Yvette Hoitink, MLitt, CG®, QG™ is a professional genealogist, writer, and lecturer from the Netherlands who helps people find their ancestors from the Netherlands and its former colonies, including New Netherland. She has a Master of Letters in Family and Local History from the University of Dundee, and holds the Certified Genealogist and Qualified Genealogist credentials.
Do you need a genealogist in the Netherlands to help you with your research?
Please read what Yvette can do for you.
This Dutch Genealogy webinar gives you a great introduction to researching your Dutch ancestors. Requires a Legacy FamilyTreeWebinar subscription to watch. [Affiliate link]